Copenhagen, Dec. 14 (Reuters): The European Union has thrown open its doors to 10 mostly former Communist east European countries, ending years of tortuous negotiations and redefining the continent’s boundaries.

Even as EU leaders agreed to the largest expansion in the bloc’s 45-year history, further radical upheaval lay over the horizon, with mainly Muslim Turkey promising that it would be ready to start formal entry talks by 2004.

The decision to add 10 new members to the present 15 came at the end of an intense two-day summit and means that the EU’s population will grow by 20 per cent to 450 million people, creating an economic colossus to rival the US.

“Europe is spreading its wings in freedom, in prosperity and in peace. This is a truly proud moment for the European Union,” Danish Prime Minister Anders Fogh Rasmussen, the summit host, said in an emotional final speech yesterday.

The Big Bang is scheduled for May 2004, giving the newcomers little over a year to secure public backing for their EU entry in a series of referendums and ready their economies for the shock of hooking up to the wealthy western powerhouse.

Yesterday’s deal ended months of haggling over terms, with Poland, the biggest and most demanding candidate, battling until the last minute to win a slightly improved financial package.

Champagne flowed to celebrate the accord, but Turkey did not share the general delight, having failed to get a fixed date for kicking off its membership talks, despite energetic lobbying by US President George W. Bush on its behalf.

Instead, Ankara was told that the long-awaited talks could start only if it was deemed to have met the bloc’s strict standards on human rights and democracy by the end of 2004.

After an initial frisson of anger, Turkish leaders said they would plough ahead with their reform programme and would be ready for negotiations within two years.

The countries that were invited to join in May 2004 were Poland, Hungary, the Czech Republic, Slovakia, Slovenia, Estonia, Lithuania, Latvia, Cyprus and Malta. A summit draft statement backed Bulgaria and Romania’s aim of entry in 2007.

Polish Prime Minister Leszek Miller, who irked many EU member states by his uncompromising brinkmanship, waxed lyrical when the deal was finally done.

“Poland has made a great historic step forward. We shake off the burden of Yalta,” he said, referring to the 1945 division of Europe into Soviet and Western spheres of influence after World War II.